Re: speed of querry? - Mailing list pgsql-performance

Joel Fradkin

Turning off merg joins seems to of done it but what do I need to do so I am
not telling the system explicitly not to use them, I must be missing some
setting?

On linux box.

explain analyze select * from viwassoclist where clientnum ='SAKS'

"Hash Join  (cost=988.25..292835.36 rows=15773 width=113) (actual
time=23.514..3024.064 rows=160593 loops=1)"
"  Hash Cond: ("outer".locationid = "inner".locationid)"
"  ->  Hash Left Join  (cost=185.57..226218.77 rows=177236 width=75) (actual
time=21.147..2221.098 rows=177041 loops=1)"
"        Hash Cond: (("outer".jobtitleid = "inner".id) AND
(("outer".clientnum)::text = ("inner".clientnum)::text))"
"        ->  Seq Scan on tblassociate a  (cost=0.00..30851.25 rows=177236
width=53) (actual time=0.390..1095.385 rows=177041 loops=1)"
"              Filter: ((clientnum)::text = 'SAKS'::text)"
"        ->  Hash  (cost=152.55..152.55 rows=6604 width=37) (actual
time=20.609..20.609 rows=0 loops=1)"
"              ->  Seq Scan on tbljobtitle jt  (cost=0.00..152.55 rows=6604
width=37) (actual time=0.033..12.319 rows=6603 loops=1)"
"                    Filter: (1 = presentationid)"
"  ->  Hash  (cost=801.54..801.54 rows=454 width=49) (actual
time=2.196..2.196 rows=0 loops=1)"
"        ->  Index Scan using ix_location on tbllocation l
(cost=0.00..801.54 rows=454 width=49) (actual time=0.111..1.755 rows=441
loops=1)"
"              Index Cond: ('SAKS'::text = (clientnum)::text)"
"Total runtime: 3120.366 ms"

here are the table defs and view if that helps. I posted the config a while
back, but can do it again if you need to see it.

CREATE OR REPLACE VIEW viwassoclist AS
 SELECT a.clientnum, a.associateid, a.associatenum, a.lastname, a.firstname,
jt.value AS jobtitle, l.name AS "location", l.locationid AS mainlocationid,
l.divisionid, l.regionid, l.districtid, (a.lastname::text || ', '::text) ||
a.firstname::text AS assocname, a.isactive, a.isdeleted
   FROM tblassociate a
   LEFT JOIN tbljobtitle jt ON a.jobtitleid = jt.id AND jt.clientnum::text =
a.clientnum::text AND 1 = jt.presentationid
   JOIN tbllocation l ON a.locationid = l.locationid AND l.clientnum::text =
a.clientnum::text;

CREATE TABLE tblassociate
(
  clientnum varchar(16) NOT NULL,
  associateid int4 NOT NULL,
  associatenum varchar(10),
  firstname varchar(50),
  middleinit varchar(5),
  lastname varchar(50),
  ssn varchar(18),
  dob timestamp,
  address varchar(100),
  city varchar(50),
  state varchar(50),
  country varchar(50),
  zip varchar(10),
  homephone varchar(14),
  cellphone varchar(14),
  pager varchar(14),
  associateaccount varchar(50),
  doh timestamp,
  dot timestamp,
  rehiredate timestamp,
  lastdayworked timestamp,
  staffexecid int4,
  jobtitleid int4,
  locationid int4,
  deptid int4,
  positionnum int4,
  worktypeid int4,
  sexid int4,
  maritalstatusid int4,
  ethnicityid int4,
  weight float8,
  heightfeet int4,
  heightinches int4,
  haircolorid int4,
  eyecolorid int4,
  isonalarmlist bool NOT NULL DEFAULT false,
  isactive bool NOT NULL DEFAULT true,
  ismanager bool NOT NULL DEFAULT false,
  issecurity bool NOT NULL DEFAULT false,
  createdbyid int4,
  isdeleted bool NOT NULL DEFAULT false,
  militarybranchid int4,
  militarystatusid int4,
  patrontypeid int4,
  identificationtypeid int4,
  workaddress varchar(200),
  testtypeid int4,
  testscore int4,
  pin int4,
  county varchar(50),
  CONSTRAINT pk_tblassociate PRIMARY KEY (clientnum, associateid),
  CONSTRAINT ix_tblassociate UNIQUE (clientnum, associatenum)
)
CREATE TABLE tbljobtitle
(
  clientnum varchar(16) NOT NULL,
  id int4 NOT NULL,
  value varchar(50),
  code varchar(16),
  isdeleted bool DEFAULT false,
  presentationid int4 NOT NULL DEFAULT 1,
  CONSTRAINT pk_tbljobtitle PRIMARY KEY (clientnum, id, presentationid)
)
CREATE TABLE tbllocation
(
  clientnum varchar(16) NOT NULL,
  locationid int4 NOT NULL,
  districtid int4 NOT NULL,
  regionid int4 NOT NULL,
  divisionid int4 NOT NULL,
  locationnum varchar(8),
  name varchar(50),
  clientlocnum varchar(50),
  address varchar(100),
  address2 varchar(100),
  city varchar(50),
  state varchar(2) NOT NULL DEFAULT 'zz'::character varying,
  zip varchar(10),
  countryid int4,
  phone varchar(15),
  fax varchar(15),
  payname varchar(40),
  contact char(36),
  active bool NOT NULL DEFAULT true,
  coiprogram text,
  coilimit text,
  coiuser varchar(255),
  coidatetime varchar(32),
  ec_note_field varchar(1050),
  locationtypeid int4,
  open_time timestamp,
  close_time timestamp,
  insurance_loc_id varchar(50),
  lpregionid int4,
  sic int4,
  CONSTRAINT pk_tbllocation PRIMARY KEY (clientnum, locationid),
  CONSTRAINT ix_tbllocation_1 UNIQUE (clientnum, locationnum, name),
  CONSTRAINT ix_tbllocation_unique_number UNIQUE (clientnum, divisionid,
regionid, districtid, locationnum)
)

It strikes me as odd that the thing isn't considering hash joins for
at least some of these steps.  Can you force it to (by setting
enable_mergejoin off)?  If not, what are the datatypes of the join
columns exactly?

            regards, tom lane